fractional distillation Flashcards
What is the primary purpose of fractional distillation?
To separate hydrocarbon fractions from crude oil
Crude oil is a complex mixture of various hydrocarbons, primarily alkanes.
What is the main component of crude oil?
Hydrocarbons
Most hydrocarbons in crude oil are alkanes.
What happens to crude oil during the heating process in fractional distillation?
Most of it evaporates
The gases produced enter the fractionating column.
Describe the temperature gradient in a fractionating column.
Hot at the bottom and cooler at the top
This gradient is crucial for the separation of hydrocarbons.
Why do shorter hydrocarbons remain as gases at lower temperatures?
They have low boiling points
Shorter hydrocarbons do not condense until they reach the cooler upper part of the column.
What occurs to longer hydrocarbons as they move up the fractionating column?
They condense back into liquids
Longer hydrocarbons have high boiling points, so they require higher temperatures to remain gaseous.
Where do longer hydrocarbons condense in the fractionating column?
Near the bottom
They drain out of the column early on due to the cooler temperatures higher up.
What is the result of fractional distillation of crude oil?
Separation into different fractions
Each fraction contains a mixture of hydrocarbons with similar properties.
What do all hydrocarbons in one fraction have in common?
Similar number of carbon atoms
This similarity leads to comparable boiling points.
Fill in the blank: Fractional distillation separates crude oil into fractions that contain a mixture of hydrocarbons with _______.
similar boiling points
This is due to the similar number of carbon atoms in the hydrocarbons.
